Effect of nano-modified titanium surface with alkali heat treatment on early adhesion and growth of osteoblasts / 中国组织工程研究

BACKGROUND:Nanostructure modification of pure titanium surface is a hot research field of titanium implant surface treatment. OBJECTIVE:To evaluate the effect of nano-modified titanium surface treated with alkali heat treatment on early adhesion and growth of osteoblasts. METHODS:Four-grade pure titanium sheets with a diameter of 15 mm and a thickness of 1.5 mm were taken and processed in three groups:the smooth treatment group was polished step by step with 250 mesh,800 mesh,and 1 500 mesh silicon carbide sandpaper.In the sandblasting group,the smoothed titanium sheet was sandblasted with 100 μm Al2O3 particles at 0.45 MPa pressure,and then the acid etching was carried out.In the alkali heat treatment group,the smoothed titanium sheet was placed in the reactor,immersed in 10 mol/L NaOH solution,and heated in the oven at 100 ℃for 12 hours.The surface morphology,roughness,and hydrophilicity of three groups of titanium sheets were measured.MG63 osteoblasts were inoculated on the surface of three groups of titanium tablets,and the adhesion of the cells was observed by immunofluorescence staining. RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that the surface of titanium sheets in the smooth treatment group had uniform scratches;the surface of titanium sheets in the sandblasting group was uneven,and the surface of titanium sheets in the alkali heat treatment group had uniform nanoscale three-dimensional pore morphology.The roughness value of the titanium sheets in sandblasting and alkali heat treatment groups was higher than that in the smooth treatment group(P<0.05),and the water contact angle was lower than that in the smooth treatment group(P<0.05).(2)Immunofluorescence staining after 3 and 6 hours of inoculation of MG63 cells showed that the number of adhesion cells on the surface of the titanium sheet in the sandblasting group and alkali heat treatment group was higher than that in the smooth treatment group(P<0.05).Immunofluorescence staining 12 hours after inoculation showed that compared with the smooth treatment group,the actin skeleton of cells on the surface of titanium sheets in the sandblasting group and alkali heat treatment group was more extended,and most cells extended stronger pseudopodia,which was conducive to subsequent intercellular signal transduction and intercellular interaction.(3)The results showed that the nanostructures with certain biological activity could be prepared on the surface of a titanium sheet by alkali heat treatment,which was conducive to the early adhesion of osteoblasts.

The effects of low intensity pulsed ultrasound on the osteogenetic differentiation of BMSCs on titanium with different surface topography / 实用口腔医学杂志

Objective:To observe the effects of low intensity pulsed ultrasound(LIPUS) on the osteogenic differentiation of rat bone marrow mesenchymal stem cells(BMSCs) on titanium surface.Methods:BMSCs from Wistar rat bone marrow were respectively cultured on the flat titanium surface and the large grain blast acid etched(SLA) titanium surface,and induced by mineralization medium.Then,the cells were interfered by LIPUS and a control condition.Alkaline phosphatase(ALP) were quantitative determinated after 3 and 7 d mineralization induction respectively,ALP staining were observed after 14 d induction.Alizarin red staining were observed after 21 d mineralization induction.Osteogenic related protein and gene expressions were detected after mineralization induction.Results:ALP in culture medium of LIPUS group was higher than that of the control group after 3 d and 7 d mineralization induction(P＜0.05).LIPUS group showed stronger ALP staining and alizarin staining,and more mineralized nodules than control group.The expression of osteogenic related proteins,including Runx2,BMP2,OPN in LIPUS group increased.Osteogenic related genes expression,including ALP,Runx2,BMP2,OPN,OCN and Col-1 of the LIPUS group increased.Conclusion:The osteogenic differentiation of BMSCs on the fiat titanium surface or SLA titanium surface can be promoted by LIPUS.

Biological characterization of implant surfaces - in vitro study / Caracterização biológica de superfície de titânio - estudo in vitro

Objective: Evaluate the biological performance of titanium alloys grade IV under different surface treatments: sandblasting and double etching (Experimental surface 1; Exp1, NEODENT); surface with wettability increase (Experimental surface 2; Exp2, NEODENT) on response of preliminary differentiation and cell maturation. Material and method: Immortalized osteoblast cells were plated on Exp1 and Exp2 titanium discs. The polystyrene plate surface without disc was used as control group (C). Cell viability was assessed by measuring mitochondrial activity (MTT) at 4 and 24 h (n = 5), cell attachment was performed using trypan blue exclusion within 4 hours (n = 5), serum total protein and alkaline phosphatase normalization was performed at 4, 7 and 14 days (n = 5). Data were analyzed using one-way ANOVA and Tukey test. Result: The values of cell viability were: 4h: C - 0.32±0.01A; Exp1 - 0.34±0.08A; Exp2 - 0.29±0.03A. 24h: C - 0.43±0.02A; Exp1 - ; 0.39±0.01A; Exp2 - 0.37±0.03A. The cell adhesion counting was: C -85±10A; Exp1- 35±5B; Exp2& - 20±2B. The amounts of serum total protein were 4d: C - 40±2B; Exp1 - 120±10A; Exp2 -130±20A. 7d: C 38±2B; Exp1 - 75±4A; Exp2 -70±6A. 14 d: C - 100±3A; Exp1 - 130±5A; Exp2 - 137±9A. The values of alkaline phosphatase normalization were: 4d: C - 2.0±0.1C; Exp1 - 5.1±0.8B; Exp2 - 9.8±2.0A<. 7d: C -1.0±0.01C; Exp1 - 5.3±0.5A; Exp2 - 3.0±0.3B. 14 d: C - 4.1±0.3A; Exp1 - 4.4±0.8A; Exp2 - 2.2±0.2B. ...

Objetivo: Avaliar o desempenho biológico de ligas de titânio grau IV submetidos a diferentes tratamentos de superfície - jateamento e duplo ataque ácido (Superfície experimental 1; Exp1, NEODENT) e superfície com aumento na molhabilidade (Superfície experimental 2; Exp2, NEODENT) em resposta preliminar de diferenciação e maturação celular. Material e método: Foram plaqueados osteoblastos imortalizados sobre discos de titânio de Exp1 e Exp2 e como controle o poço da placa de cultura sem disco (C). Empregou-se ensaios de viabilidade celular (MTT) em 4 e 24 horas (n = 5), adesão celular em 4 horas (n = 5), dosagem de proteínas totais e fosfatase alcalina normalizada em 4, 7 e 14 dias (n = 5). Os dados foram analisados por ANOVA em fator único seguido de teste de Tukey. Resultado: Os valores de viabilidade celular foram: 4h: C - 0,32±0,01A; Exp1 - 0,34±0,08A; Exp2 - 0,29±0,03A. 24h: C - 0,43±0,02A; Exp1 - 0,39±0,01A; Exp2 - 0,37±0,03A. A contagem de adesão celular foi: C - 85±10A; Exp1 - 35±5B; Exp2 - 20±2B. Os valores de proteínas totais foram: 4d: C - 40±2B; Exp1 - 120±10A; Exp2 - 130±20A. 7d: C - 38±2B; Exp1 - 75±4A; Exp2 - 70±6A. 14 d: C - 100±3A; Exp1 - 130±5A; Exp2 - 137±9A. Os valores de fosfatase alcalina normalizada foram: 4d: C - 2,0±0,1C; Exp1 - 5,1±0,8B; Exp2 - 9,8±2,0A, 7d: C - 1,0±0,01C; Exp1 - 5,3±0,5A; Exp2 - 3,0±0,3B, 14 d: C - 4,1±0,3A; Exp1 - 4,4±0,8A; Exp2 - 2,2±0,2B. Letras diferentes representam ...

Effects of Titanium Surfaces on the Developmental Profile of Monocytes/Macrophages

Due to the critical role of monocytes/macrophages (Mϕ) in bone healing, this study evaluated the effects of bio-anodized, acid-etched, and machined titanium surfaces (Ti) on Mϕ behavior. Cells were separated from whole human blood from 10 patients, plated on Ti or polystyrene (control) surfaces, and cultured for 72 h. At 24, 48 and 72 h, cell viability, levels of IL1β, IL10, TNFα, TGFβ1 inflammatory mediators, and nitric oxide (NO) release were analyzed by mitochondrial colorimetric assay (MTT assay) and immunoenzymatic assays, respectively. Real-time PCR was used to verify the expression of TNFα and IL10 at 72 h. The data were subjected to a Kruskal-Wallis analysis. IL1β, TNFα and TGFβ1 release were not significantly different between the Ti surfaces (p>0.05). The presence of NO and IL10 was not detected in the samples. Cell viability did not differ between the samples cultivated on Ti and those cultivated on control surfaces, except at 24 h (p=0.0033). With respect to the mediators evaluated, the surface characteristics did not induce a typical Th1 or Th2 cytokine profile, although the cell morphology and topography were influenced by the Ti surface during the initial period.

Devido ao papel crítico dos monócitos / macrófagos (Mϕ) na cicatrização óssea, este estudo avaliou os efeitos de superficies de titânio (Ti) bio-anodizada, ataque ácido e usinada sobre o comportamento Mϕ. As células foram separadas a partir de sangue humano de 10 pacientes, plaqueadas em Ti ou superfícies de poliestireno (controle), e cultivadas durante 72 h. Às 24, 48 e 72 h, a viabilidade celular e IL1β, IL10, TNFα, TGFβ1 e liberação de óxido nítrico foram analisados por ensaio colorimétrico mitocondrial (MTT) e ensaios imunoenzimáticos, respectivamente. PCR em tempo real foi utilizado para verificar a expressão de TNFα e IL-10 às 72 h. Os dados foram submetidos a uma análise de Kruskal-Wallis. IL1β autorização, TNFα e TGFβ1, não foram significativamente diferentes entre as superfícies de Ti (p>0,05). A presença de NO e de IL-10 não foi detectada nas amostras. A viabilidade celular não diferiu entre as amostras cultivadas em Ti e aquelas cultivadas em superfícies de controle, exceto às 24 h (p=0,0033). No que diz respeito aos mediadores avaliados, as características da superfície, não induziu resposta típica de citocinas Th1 ou Th2, embora a morfologia da célula e a topografia foram influenciadas pela superfície de Ti, durante o período inicial.

Magnesium vs. machined surfaced titanium - osteoblast and osteoclast differentiation

PURPOSE: This study focused on in vitro cell differentiation and surface characteristics in a magnesium coated titanium surface implanted on using a plasma ion source. MATERIALS AND METHODS: 40 commercially made pure titanium discs were prepared to produce Ti oxide machined surface (M) and Mg-incorporated Ti oxide machined surface (MM). Surface properties were analyzed using a scanning electron microscopy (SEM). On each surface, alkaline phosphatase (ALP) activity, alizarin red S staining for mineralization of MC3T3-E1 cells, and quantitative analysis of osteoblastic gene expression, were evaluated. Actin ring formation assay and gene expression analysis of TRAP and GAPDH performing RT-PCR were performed to characterize osteoclast differentiation on mouse bone marrow-derived macrophages (BMMs). RESULTS: MM showed similar surface morphology and surface roughness with M, but was slightly smoother after ion implantation at the micron scale. M was more hydrophobic than MM. No significant difference between surfaces on ALP activity at 7 and 14 days were observed. Real-time PCR analyses showed similar levels of mRNA expression of the osteoblast phenotype genes; osteopontin (OPN), osteocalcin (OCN), bone sialoprotein (BSP), and collagen 1 (Col 1) in cell grown on MM at 7, 14 and 21 days. Alizarin red S staining at 21 days showed no significant difference. BMMs differentiation increased in M and MM. Actin ring formation assay and gene expression analysis of TRAP showed osteoclast differentiation to be more active on MM. CONCLUSION: Both M and MM have a good effect on osteoblastic cell differentiation, but MM may speed the bone remodeling process by activating on osteoclast differentiation.

Evaluation of titanium surface properties by Nd: YVO4 laser irradiation: pilot study / 대한치과보철학회지

PURPOSE: This study was conducted to evaluate the roughness and surface alternations of three differently blasted titanium discs treated by Nd: YVO4 Laser irradiation in different conditions. MATERIALS AND METHODS: Thirty commercially pure titanium discs were prepared and divided into three groups. Each group was consisted of 10 samples and blasted by ZrO2 (zirconium dioxide), Al2O3 (aluminum oxide), and RBM (resorbable blasted media). All the samples were degreased by ultrasonic cleaner afterward. Nine different conditions were established by changing scanning speed (100, 300, 500 mm/s) and repetition rate (5, 15, 35 kHz) of Nd: YVO4 Laser (Laser Pro D-20, Laserval Korea(R) Seoul, South Korea). After laser irradiation, a scanning electron microscope, X-ray diffraction analysis, energy dispersive X-ray spectroscopic analysis, and surface roughness analysis were used to assess the roughness and surface alternations of the samples. RESULTS: According to a scanning electron microscope (SEM), titanium discs treated with laser irradiation showed characteristic patterns in contrast to the control which showed irregular patterns. According to the X-ray diffraction analysis, only Al2O3 group showed its own peak. The oxidation tendency and surface roughness of titanium were similar to the control in the energy dispersive X-ray spectroscopic analysis. The surface roughness was inversely proportional to the scanning speed, whereas proportional to the repetition rate of Nd: YVO4. CONCLUSION: The surface microstructures and roughness of the test discs were modified by the radiation of Nd: YVO4 laser. Therefore, laser irradiation could be considered one of the methods to modify implant surfaces for the enhancement of osseointegration.

Comparison of biofilm on titanium and zirconia surfaces: in vivo study / 대한치과보철학회지

PURPOSE: This study was conducted to compare in vivo biofilm formation on titanium surface and zirconia surface. MATERIALS AND METHODS: For biofilm formation on titanium and zirconia in oral cavity, after producing oral appliances using acrylic resin and orthodontic wire tailored to 9 subjects, we made titanium and zirconia specimens (6 mm x 6 mm x 2 mm), fixed them on oral appliances and maintained them in oral cavity of test subjects for 24 and 72 hours. Test subjects who have equipped two pairs of specimens maintained oral hygiene not by using toothpaste but only by tooth brushing. After 24 and 72 hours, we removed and observed specimens through scanning electron microscopy (SEM). RESULTS: Biofilm formation showed large deviation depending on individuals. For formation comparison between titanium and zirconia for 24 hours, zirconia showed less biofilm formation than titanium. Biofilm formation showed large deviation depending on individuals. As for formation comparison between zirconia and titanium, the degree of biofilm formation in zirconia was less than it was in titanium after a lapse of 24 hours. The result of biofilm formation in 72 hours trial show that zirconia has an inclination to formate less biofilm than it was in titanium. CONCLUSION: Based on the above results, we can conclude that early biofilm formation in oral cavity was influenced by difference of abutment materials.

Análisis químico y topográfico de la superfície de implantes dentarios mediante espectroscopia de fotoelectrones y microscopía electrónica de barrido: estudio preliminar / Chemical and topographic analysis of dental implant surfaces using photoelectron spectroscopy and scanning electron microscopy: preliminary study

El objetivo de este estudio fue analizar la composición química y la topografía superficial de implantes de titanio comercialmente puro, obtenidos de 3 marcas comerciales utilizadas actualmente en odontología. Fueron analizados 6 implantes de titanio de los siguientes sistemas: SIN, P-I philosophy y Neodent. Este material fue dividido en 3 grupos de 3 implantes cada uno. Para determinar la composición química de la superficie fue utilizada la técnica de Espectroscopia de Fotoelectrones Excitada por rayos-X (XPS), mientras que para caracterizar la topografía superficial fue utilizada Microscopia electrónica de barrido. Titanio, Carbono Silicio y Oxigeno fueron identificados en todas las muestras analizadas. Otros elementos contaminantes identificados fueron Silicio, Aluminio, azufre, plomo, Fósforo, Calcio, Sodio, Nitrógeno y Carbono. Fueron identificadas impurezas en la superficie de todos los implantes analizados. Consideramos necesarios otros estudios que relacionen permanentemente la presencia y concentración de estos elementos con el proceso de oseointegración...

The aim of this study was to analyze the chemical composition and surface topography of commercially pure titanium implants, obtained from 03 trademarks frequently used in dentistry. There were 9 titanium implants of the following systems: SIN, P-I philosophy and Neodent. These materials were divided into 3 groups, with 3 implants in each group. Photoelectron Spectroscopy Excited by X-ray (XPS) was used to determine the chemical composition, while to characterize the surface topography we used Scanning Electron Microscopy (SEM). Titanium, carbon silicon and oxygen were identified in all samples analyzed. Other contaminants were: silicon, aluminum, sulfur, lead, phosphorus, calcium, sodium, nitrogen and carbon. We identified impurities on the surface of all implants analyzed. We consider necessary to development more studies relating the presence and concentration of these elements with the osseointegration process...

Análise microbiológica comparativa da ação de diferentes agentes descontaminantes sobre superfícies de titânio / Microbiological comparison of different decontaminant agents on rough and smooth titanium surfaces: microbiological analysis

Os implantes de titânio estabeleceram-se, ao longo do tempo, como uma opção de tratamento com grande índice de sucesso. Entretanto, falhas são passíveis de ocorrer, devido à exposição de suas superfícies ao meio bucal, imediatamente ou até muito tempo passado de sua implantação. Estas superfícies de titânio podem se infectar por bactérias e seus produtos, de forma semelhante à que ocorre na superfície de raízes dentais. Tais contaminantes intensificam a resposta inflamatória, além de alterar a estrutura superficial do implante podendo dar origem às doenças peri-implantares, como a mucosite peri-implantar e a peri-implantite. Para o tratamento destas doenças, diversos métodos de descontaminação de superfícies de implantes têm sido propostos, incluindo o uso substâncias anti-sépticas, jatos abrasivos, ácidos, antibióticos e lasers. O objetivo foi avaliar comparativamente a capacidade de descontaminação do peróxido de hidrogênio a 1,5 % (H2O2), do gluconato de clorexidina a 0,12% (CLX) e do soro fisiológico (SF) já que, até o momento, nenhuma metodologia está estabelecida como padrão ouro para a limpeza superficial. Placa bacteriana foi colhida de sítios de doença periodontal crônica para contaminação de discos de titânio de superfícies lisas e rugosas. Posteriormente, os discos foram submersos em 10 mL das substâncias estudadas por 1 minuto, friccionados com swab e enxaguados em solução fisiológica. Discos controle (C) foram somente enxaguados em soro fisiológico. Desta forma resultaram os seguintes grupos de estudo, constituídos de 5 discos de cada tipo de superfície lisa (L) e rugosa (R): H2O2 R , CLXR, SFR, CR, H2O2L, CLXL , SFL e CL. A avaliação do potencial descontaminante das substâncias foi realizada através da quantificação do crescimento bacteriano pela contagem das unidades formadoras de colônia (UFCs) após semeadura em Agar-brucella e incubação em jarra de CO2 a 37oC por 24 horas. Os resultados após descontaminação foram comparados através da...

Actually, the titanium implants are a successful option of treatment in Dentistry. However, failures are possible to occur due to surface exposition to oral environment immediately or lately after its implantation. The titanium implants surfaces can be infected by bacteria and its products similarly to dental roots surfaces. The contaminants turn the inflammatory response tissues more intensive and them alter the surface structure of the implant and cause periimplant diseases like mucositis and peri-implantitis. Several methods of treatment for those diseases have been proposed in the literature, including antiseptics rinses, abrasives air powder, acids, antibiotics and lasers. The aim of this work was to comparatively evaluate the potential for decontamination of the hydrogen peroxide at 1,5% (H2O2), the 0,12% chlorhexidine gluconate (CLX) and the saline solution (SF) as cleaning methods, once until this moment there is not a gold standard method established for this purpose. Bacterial plaque harvested from sites of chronic periodontal disease was used to contaminate smooth and rough surfaces of titanium. Subsequently, decontamination procedures were realized by submerging the discs in 10 ml of the studied substances for 1 minute, cleaned by rubbing with swab and washed on saline solution. Control discs (C) were only washed in saline solution. The following test groups composed by 5 discs of each surface, smooth (L) and rough (R):, were then originated: H2O2 R , CLXR, SFR, CR, H2O2L, CLXL , SFL and CL. The decontaminant potential of studied substances was realized by counting the colony forming units after seeding in Agar-brucella, under anaerobiosis condition for 24 hours under 37oC. The data analysis was made by Variance Analysis (ANOVA) at 5% of significance level. The results lead to the following conclusions: the chronic periodontal biofilm adhesion was possible on smooth and rough titanium surfaces; the surface characteristic had no significant...

Diferenciação de célula-tronco hematopoética periférica humana em osteoblasto sobre diferentes superfícies de implantes de titânio / Cell differentiation of human haematopoietic stem cell (hHSC) to osteoblast in different surfaces of titanium implant

A associação dos implantes de titânio com tecido ósseo desenvolvido em cultura poderá contribuir para o tratamento de casos clínicos complexos. O objetivo deste trabalho foi viabilizar a formação do tecido a partir da cultura de célula-tronco hematopoética periférica humana (CTHPh) e avaliar o seu crescimento em implantes de titânio, com diferentes superfícies e tamanhos, para definir o melhor resultado. As CTHPhs foram coletadas no sangue periférico por aféresis e cultivadas em meio D-MEN modificado, em placas de cultura com 24 poços, onde foram incluídos implantes de titânio de 3 e 7mm com superfície lisa e texturizada (por jateamento e ataque de ácido), durante 29 dias. A cultura, com corpo-de-prova identificado, teve “cultura controle” sem o corpo-de-prova. Foram avaliados: adesão celular, após 4 horas da inclusão e no 280 dia (D28); curva de crescimento (D1 e D28); atividade da fosfatase alcalina e proteínas totais dos sobrenadantes das culturas (4 horas e D4, D6, D9, D12, D16, D22, D28). Usou-se estatística descritiva na apresentação dos resultados. Concluiu-se que o tamanho dos implantes (3 ou 7mm) não influenciou no desenvolvimento da cultura; quanto à superfície, os implantes texturizados mostraram maior crescimento e adesão celular, maiores valores de atividade da fosfatase alcalina e proteínas totais, apontando para efeito favorável na formação de tecido ósseo in vitro.

The association of titanium implants with cultured bone tissue could contribute to the treatment of complex affections. The aim of this study was to obtain tissue formation from human haematopoietic stem cell (hHSC) and to evaluate the growth in titanium implants, with different surfaces and sizes in order to determine the best results. The hHSC was obtained from blood and cultured for 29 days in 24-well tissue culture plates containing Dulbecco's modified essential medium (Gibco®) and titanium implants of 3 and 7mm with smooth and rough surfaces. Negative controls were included. Were evaluated: cell adhesion after 4 hours of inoculation and again at day 28 (D28): growth curve at day 1 (D1) and day 28 (D28): activity of alkaline phosphatase and total protein from culture supernatant (4 hours, D4, D6, D9, D12, D16, D22, D28). Were applied descriptive statistics to the data. It was concluded that the size of implant (3 or 7mm) did not interfere with development of the culture. Rough surface implants showed increased growth and cell adhesion, greater alkaline phosphatase and total proteins activity, indicating favorable effect to the formation of bone tissue in-vitro.

Wettability and drug delivery of functionally graded nano-micro porous titanium surface / 대한치과보철학회지

STATEMENT OF PROBLEM: It is known that an anodic oxidation technique, one of the methods for the implant surface treatment, remarkably increased surface area, enhanced wettability and accelerated the initial bone healing. Purpose: This study was performed to evaluate the wettability of anodized titanium surface which has a nanotubular structure, to assess osseointegration after the placement of implant with nano-size tubes on tibia of rats and to analyze quantitatively transferable rhBMP-2 on each surface. MATERIAL AND METHOD: Four different kinds of surface-treated titanium discs (polished (machined surface) group, micro (blasting surface) group, nano (anodizedmachined surface) group, and nano-micro (anodized-blasting surface) group) were fabricated (n=10). Three different media were chosen to measure the surface contact angles; distilled water, plasma and rhBMP-2 solution. After a single drop (0.025 ml) of solution, the picture was taken with the image camera, and contact angle was measured by using image analysis system. For the test of osseointegration, 2 kinds of anodized surface (anodized-machined surface, anodized-blasting surface) implants having 2.0 mm in diameter and 5.0 mm in length inserted into the tibia of Wistar rats. After 3 weeks, tibia were harvested and the specimens were stained with hematoxylin and eosin for histological analysis. To test the possibility of drug delivery, after soaking sample groups in the concentration of 250 ng/ml of rhBMP-2 for 48 hours, the excess solution of rhBMP-2 were removed. After that, they were lyophilized for 24 hours, and then the rhBMP-2 on the surface of titanium was resolved for 72 hours in PBS. All the extracted solution was analyzed by ELISA. One-way analysis of variance (ANOVA) was performed on the data. RESULTS: The wettability is improved by anodic oxidation. The best wettability was shown on the nano-micro group, and it was followed by nano group, micro group, and polished group. In the histological findings, all implants showed good healing and the new bone formation were observed along the implant surface. After 3 days, nano-micro group delivered the most amount of rhBMP-2, followed by nano group, micro group, and polished group. CONCLUSION: It indicated that anodic oxidation on blasting surface produce functionally graded nano-micro porous structure and enhance hydrophilicity of the surface and osseointegration. The findings suggest that the nano-micro porous structure could be a useful carrier of osteogenic molecules like rhBMP-2.

A study on the biological characteristics of modified titanium surface / 대한치주과학회지

PURPOSE: The purpose of this research is to study about initial adhesion, proliferation and activation of osteoblast to titanium surface treated with machined, hydroxyapatite coating, resorbable blast material blasting and anodizing method. MATERIAL AND METHODS: After treating the titanium surface of each block with machined, impurities were removed and sterilized. The number of cells attached from cultured osteoblast of respective experimental groups were measured at 1, 4, 7, and 14day and alkaline phosphatase, calcium, and inorganic phosphate concentration of cultured solution was measured. RESULT: Anodizing group showed the highest rate of cell attachment and proliferation activity. RBM treated group showed the highest increasing on their alkaline phosphatase activity, on the calcium apposition, on inorganic phosphate apposition of 1 and 4 days in cultured osteoblast to compare with other groups. CONCLUSION: On the basis of these findings, we conclude that surface modification of titanium was profoundly effected on the attachment, proliferation and activation of osteoblast in initial stage osseointegration.

DNA microarray analysis of gene expression of MC3T3-E1 osteoblast cell cultured on anodized- or machined titanium surface / 대한치주과학회지

PURPOSE: The aim of this study was to evaluate adhesion and gene expression of the MC3T3-E1 cells cultured on machined titanium surface (MS) and anodized titanium surface (AS) using MTT test, Scanning electron micrograph and cDNA microarray. MATERIALS AND METHODS: The MTT test assay was used for examining the proliferation of MC3T3-E1 cells, osteoblast like cells from Rat calvaria, on MS and AS for 24 hours and 48 hours. Cell cultures were incubated for 24 hours to evaluate the influence of the substrate geometry on both surfaces using a Scanning Electron Micrograph (SEM). The cDNA microarray Agilent Rat 22K chip was used to monitor expressions of genes. RESULTS: After 24 hours of adhesion, the cell density on AS was higher than MS (p0.05). AS had the irregular, rough and porous surface texture. After 48 hours incubation of the MC3T3-E1 cells, connective tissue growth factor (CTGF) was up-regulated on AS than MS (more than 2 fold) and the insulin-like growth factor 1 receptor was down-regulated (more than 2 fold) on AS than MS. CONCLUSION: Microarray assay at 48 hours after culturing the cells on both surfaces revealed that osteoinductive molecules appeared more prominent on AS, whereas the adhesion molecules on the biomaterial were higher on MS than AS, which will affect the phenotype of the plated cells depending on the surface morphology.

A comparison of fracture strengths of porcelain-fused-to-titanium crown among titanium surface coating treatments / 대한치과보철학회지

STATEMENT OF PROBLEM: Titanium and its alloy, with their excellent bio-compatibility and above average resistance to corrosion, have been widely used in the field of dentistry. However, the excessive oxidization of titanium which occurs during the process of firing on porcelain makes the bonding of titanium and porcelain more difficult than that of the conventional metal-porcelain bonding. To solve this problem related to titanium-porcelain bonding, several methods which modify the surfaces, coat the surfaces of titanium with various pure metals and ceramics, to enable the porcelain adhesive by limiting the diffusion of oxygen and forming the adhesive oxides surfaces, have been investigated. PURPOSE: The purpose of this study was to know whether the titanium-porcelain bonding strength could be enhanced by treating the titanium surface with gold and TiN followed by fabrication of clinically applicable porcelain-fused-to-titanium crown. MATERIAL AND METHOD: The porcelain-fused-to-titanium crown was fabricated after sandblasting the surface of the casting titanium coping with Al2O3 and treating the surface with gold and TiN coating followed by condensation and firing of ultra-low fusing porcelain. To compare with porcelain-fused-to-titanium crowns, porcelain-fused-to-gold crowns were fabricated and used as control groups. The bonding strengths of porcelain-fused-to-gold crowns and porcelain-fused-totitanium crowns were set for comparison when the porcelain was fractured on purpose to get the experimental value of fracture strength. Then, the surface were examined by SEM and each fracturing pattern were compared with each other. RESULT: Those results are as follows. 1. The highest value of fracture strength of porcelain-fused-to-titanium crowns was in the order of group with gold coating, group with TiN coating, group with Al2O3 sandblasting. No statistically significant difference was found among the three (P>.05). 2. The porcelain-fused-to-gold crowns showed the highest value in bonding strength. The bonding strength of crowns porcelain-fused-to-titanium crowns of rest groups showed bonding strength reaching only 85%-94% of that of PFG, though simple comparision seemed unacceptable due to the difference in materials used. 3. The fracturing patterns between metal and porcelain showed mixed type of failure behavior including cohesive failure and adhesive failure as a similar patterns by examination with the naked eye and SEM. But porcelain-fused-to-gold crowns showed high incidence of adhesive failure and porcelain-fused-to-titanium crowns showed high incidence of cohesive failure. CONCLUSION: Above results proved that when fabricating porcelain-fused-to-titanium crowns, treating casting titanium surface with gold or TiN was able to enhance the bonding strength between titanium and porcelain. Mean value of masticatory force was found to showed clinically acceptable values in porcelain bonding strength in all three groups. However, more experimental studies and evaluations should be done in order to get better porcelain bonding strength and various surface coating methods that can be applied on titanium surface with ease.